A bipartisan measure in Congress has succeeded in temporarily blocking the latest generation of U.S. fighter jets from getting into the hands of the Erdogan regime in Turkey.

On Tuesday, the amendment to the National Defense Authorization Act (NDAA) delayed the delivery of the F-35 joint strike fighter to Turkey. The amendment requires that the Pentagon reassess Turkey’s efforts to purchase an advanced S-400 missile system from Russia.

Legislators also felt that Turkey should not receive the F-35s given the ongoing detention of U.S. Pastor Andrew Brunson and other unnamed Americans. Turkey is believed to be holding the pastor as a bargaining chip in hopes of securing the extradition of U.S.-based cleric Fethullah Gulen.

Ankara does not appear to be concerned about the transfer of the F-35s. In comments to Turkey’s state-run media, President Recep Tayyip Erdogan remained confident that the F-35s would be delivered on schedule.

Turkey continues to be a thorn in the side of the NATO alliance. The regime in Ankara has repeatedly cozied up to American adversaries in Russia and Iran. Inside Turkey, human rights travesties unfold on a daily basis. An April 2017 referendum gave Erdogan amazing powers, stripping away much of Turkey’s secular, constitutional system of checks and balances. Erdogan has leveraged an alleged coup against his government to garner even more power. He has ordered the indefinite imprisonment of tens of thousands of academics, religious minorities, activists, journalists, students, and anyone else whom he perceives as a challenge to his rule.

Moreover, some of the regime’s highest-ranking officials have been accused of supporting jihadi terrorist groups in the Middle East. Recently, Erdogan’s son-in-law (who is now Turkey’s finance minister) was connected to energy deals with the Islamic State terrorist organization. Turkey openly supports the Muslim Brotherhood and its terrorist affiliate Hamas.

Erdogan is also stirring up trouble with close American allies. This week, he claimed that Israel was the “most fascist, racist state” in the world, accusing Prime Minister Benjamin Netanyahu of following in the footsteps of Nazi leader Adolf Hitler.

Despite all of these concerns, Defense Secretary James Mattis has insisted that Turkey should still receive the Lockheed Martin F-35s. He has warned that blocking the sale could trigger a “supply chain disruption.” Turkey aspires to have a fleet of about 100 F-35s.